Analysis Safety on Fraser River The loaded chip barge Rivtow901, under tow of the tug SheenaM struck the CPR Mission Railway Bridge at night in calm weather, with good visibility. The accident occurred during the down-stream transit 75minutes after the successful completion of an up-stream transit of the same bridge. The master of the SheenaMhas over 40 years experience in the B.C. towing industry, 10years of which were spent exclusively on this section of the Fraser River. In the past decade his experience has not been with chip barges nor has it included this section of the river. While he was familiar with the annual Fraser River freshet, his most recent direct experience on this section of the river was more than 10 years ago. Downstream from Mission, the lower section of the Fraser River bears a higher concentration of marine activity. Bridges spanning the lower section of the river have sustained a higher incidence of damage as a result of being struck. In the past 25years, more than 50strikes of bridge structures by vessels or barges have been reported to the TSB. As a consequence, the Fraser River Port Authority (FraserPort), in conjunction with its marine community, have developed Standard Operating Procedures (SOP) for vessels transiting bridges within their jurisdiction in order to minimize the incidence of damage. The CPR Mission Railway Bridge at Mission is approximately 13miles upstream of the eastern boundary of Fraser Port placing it outside Fraser Port's jurisdiction. At the time of the accident, vessels transiting that bridge were governed by the general terms of the Navigable Waters Protection Act, and not subject to any specific SOPs. Although the navigation lighting on the CPR Mission Railway Bridge was operative at the time of the accident, this was not, in itself, a contributing factor. However, investigation has revealed that lighting inconsistencies exist between bridges and structures on the Fraser River. While the Navigable Waters Bridges Regulationsand the Navigable Waters Works Regulations, both pursuant to the Navigable Waters Protection Act, govern the colour and placement of the navigation lighting on bridges and lawful works in navigable waters, they are silent as to the intensity of these lights. Marine Communications and Traffic Centre (MCTS) at Victoria provides Vessel Traffic Services (VTS) for the lower Fraser River only. The nearest (traffic) CIP to the CPR Mission Railway Bridge is at New Westminster, 28miles down river. Operation of Tug/Barge in Spring Stemming a current, a vessel can often remain both stationary in a waterway and retain directional control by judicious use of rudder(s), together with adjusting the throttle setting to match the current. Travelling with the current, there must be sufficient water flow past the rudder(s), in order to maintain directional control. As a result, to approach an equivalent level of control, a vessel must develop a greater speed over the bottom than it would in still water. The master of the SheenaM,through experience, was well aware of this. He travelled 1400m upstream of the bridge before turning in order to be able to line up the tug and tow sufficiently for safe passage through the bridge. His attention was focussed on keeping both vessels as close to shore, in the reduced current, as water depth permitted. From his conning position, he knew that the current was setting the tow further away from shore than the tug. While taking this into consideration, he was also aware that he ran the risk of increasing his speed over the bottom above the minimum desired for a safe transit of the bridge. Planning is an essential element of successful passage making. However, local marine industry practice on the Fraser River does not generally include the four stages of passage planning - appraisal, planning, execution, and monitoring - as a formalized process. As a consequence, an abort point, the last position where the passage could be abandoned safely, had not been pre-established. The high forward box-wall of the Rivtow901 obscured the attitude of the barge and made it difficult to determine its aspect relative to the tug. Including a significant following current into the equation resulted in events unfolding far more rapidly than they had during the upstream passage. The unfamiliar lights of the CPR Mission Railway Bridge did not provide a clear point of reference for the master of the SheenaM as the tug made her approach at a speed enhanced by the current. Although the master was aware that the Rivtow901 was tracking in deeper water than the tug, the darkness and high forward box-wall of the barge obscured its relative attitude. This, in the mind of the master, combined with the fact that his attention was focussed for the most part on the bridge ahead caused him to realize that events had begun to deviate from his intended plan. Although never formally established, in the mind of the master, the abort point had been passed. Once committed to transiting the bridge, no other option remained. In the event that the tug and tow would not have cleared the draw, the master would have had to rely on the bridge's protection pier to absorb the impact of the barge, then guide it safely through. The protection pier has dimensions greater than the open span of the bridge it is designed to protect. Sequence of Damage Sustained Due to the height of the river (4.6m above chart datum), at the time of the accident approximately 2m of the upper squared timber portion of the protection pier was visible above the river surface. When the upper portion of the protection pier was struck by the barge, metal strapping and bolts, which connect with the wooden piles, distorted or sheared. Other bolts remained intact but were pulled bodily from position. The upper portion of the protection pier broke away from the pilings and was deflected to the north allowing the box-wall of the chip barge to make contact with the swing span of the railway bridge. The barge struck the swing span with a force sufficient to shift the span almost 4m from its pedestal. Until it was stabilized several days after the accident, there was concern that the swing span might topple into the river. The master misjudged the full effects of the strong freshet when navigating downstream. The master did not detect the onset of a loss of control of the tow due to being unfamiliar with the lights marking the navigable passage at the bridge and the configuration of the tow of the barge. Although the master of the tug had experience in other geographical areas, he did not have recent experience of transiting this section of the river during freshet. A predetermined passage plan had not been elaborated nor had a predetermined abort position been formally determined.Findings as to Causes and Contributing Factors The master misjudged the full effects of the strong freshet when navigating downstream. The master did not detect the onset of a loss of control of the tow due to being unfamiliar with the lights marking the navigable passage at the bridge and the configuration of the tow of the barge. Although the master of the tug had experience in other geographical areas, he did not have recent experience of transiting this section of the river during freshet. A predetermined passage plan had not been elaborated nor had a predetermined abort position been formally determined. Unlike similar bridges on the lower Fraser River, there were no Standard Operating Procedures governing the safe transit of this bridge by marine traffic. The location of the railway bridge controls obliges the bridge tender to remain on the swing span to operate it which exposes him to considerable risk in the event of a vessel striking and bridge damage.Findings as to Risk Unlike similar bridges on the lower Fraser River, there were no Standard Operating Procedures governing the safe transit of this bridge by marine traffic. The location of the railway bridge controls obliges the bridge tender to remain on the swing span to operate it which exposes him to considerable risk in the event of a vessel striking and bridge damage. The master was aware that while not yet at its maximum rate of flow for the year, in terms of both height above chart datum and rate of discharge, the Fraser River was significantly above annual levels and had an unusually large freshet.Other Findings The master was aware that while not yet at its maximum rate of flow for the year, in terms of both height above chart datum and rate of discharge, the Fraser River was significantly above annual levels and had an unusually large freshet. Safety Action Action Taken Following the accident, the bridge was repaired and the upstream portions of its protection pier were repaired and enhanced. In the damaged section, wooden piles were replaced by a combination of steel pipes and H beams. The nose of the protection pier was extended approximately 10m further upstream by the addition of a wooden-sheathed, triangular-shaped steel structure made from 915-mm diameter pipes driven into the river bed. CPR, in its four-year capital program, is budgeting for similar improvements to the downstream portions of the protection pier. The Navigable Waters Bridges Regulations made pursuant to the Navigable Waters Protection Act, govern bridge lighting. These Regulations are silent as to the colour and nominal range of lights prescribed. After the CPR Mission Railway Bridge re-opened, investigators from the Transportation Safety Board (TSB) viewed bridges spanning the Fraser River after dark in order to assess lighting. It has been determined that bridge lighting on the Fraser River is inconsistent with respect to nominal range. While the lighting on the CPR Mission Railway Bridge is considered appropriate, the TSB has issued a Marine Safety Advisory on these inconsistencies to the Navigable Waters Protection Division of the Canadian Coast Guard. Figure 1 of this report incorporates a section of the Canadian Hydrographic Service (CHS) chart (i.e., CHS 3488) for this section of the Fraser River. This chart indicates the CPR Mission Railway Bridge is supported by 10piers when, in fact, the bridge has 13supports. Since reconstruction the protection pier extends an additional 10m upstream. The chart also indicates the bridge displays 2white lights and 2yellow lights. The bridge now displays 10white lights and 4red lights. The TSB has brought these changes to the attention of the CHS. Upon confirmation, they will issue a Notice to Mariners advising the marine community of these changes. Rail traffic through the Fraser Canyon over the CPR Mission Railway Bridge has increased dramatically recently. As a result of this accident and in response to concerns over potential conflicts between rail and marine traffic, in April2000, the Navigable Waters Protection Division of the Canadian Coast Guard, in consultation with stakeholders, developed Standard Operating Procedures (SOP) for vessels transiting the CPR Mission Railway Bridge. These SOPs detail formal calling-in points (CIP) and procedures to the bridge tender, from each direction, for bridge transits which require the span to be opened. Additionally, in order to enhance the safety of personnel, CPR has investigated methods of operating the bridge without the need for the bridge tender to be present on the moveable portion of the span. To date, a solution has not proven economically feasible.